i did this by accident but the best way to get birdie is co-op in the underground 2 people get predator missiles hide where u purchase the missiles and just shoot the down u can also do this solo aswell

For some strange reason I did both the first two missions on Veteran (one the day after, I turned system off after doing Black Tuesday then did second next day), yet the Big Apple trophy didn't unlock. Is this glitched or do you have to do them one after another?

Also, in mission select, is there a way of knowing the Highest difficulty you've done a mission on? There was in WaW and MW2.